If same value apperas in array count +1

Hello Guys,

I have an array with nx1, now i need a code to count + 1 if the same value apperas later in the array, for example:

input = [ 1 2 3 4 1 2 3 4 1 2 3 4 ];

output = [ 1 1 1 1 2 2 2 2 3 3 3 3];

Thank you

Answer 1

[Walter Roberson]

input = [ 1 2 3 4 1 2 3 4 1 2 3 4 ];
output = sum(triu(input' == input))

output = 1×12

1 1 1 1 2 2 2 2 3 3 3 3

[First Last]

Thats it, thank you Walter :) you saved my day

Answer 2

[KSSV]

input = [ 1 2 3 4 1 2 3 4 1 2 3 4 ];
a = reshape(input,[],3)' ; 
[c,ia,ib] = unique(a,'rows') ;
ib

[First Last]

Thank you KSSV,

but i the output is a little bit diffrent